Teaching Students To See Through “Microbial Eyes"
by Mark O. Martin
The voyage of discovery is not in seeking new landscapes but in having new eyes. - Marcel Proust
At my primarily undergraduate institution (3,000 students total, 12 Biology faculty, over 50 Biology majors graduated per year), there is only one microbiology course, and it is generally taught to seniors (and not all seniors at that). Considering the power and primacy of the microbial world, I have always found that lack of coverage pedagogically unsettling. No biology major could graduate without learning a fair amount about plants; what about bacteria and archaea? It is certainly true that some classes—cell biology, genetics, and molecular biology come to mind—have aspects that intersect with matters microbial. But I find that my seniors, after a semester of my prokaryotic proselytizing, are very aware of a significant gap in their education.
This is why I would urge any and all microbiologists out there to push for more microbiology, earlier in the curriculum, both in lecture and laboratory. I do what I can to promote “microbial pride” among my seniors, as you can see from the photograph of my class this semester. I even came up with a logo, which I showed during a presentation at the American Society for Microbiology General Meeting in San Francisco last June, suggesting that we microbiologists should push to “occupy the curriculum,” intellectually speaking. After all, consider how genetics, molecular biology, and biochemistry have progressed over the past century. Now consider the path of that progress without the use of prokaryotes as a model system! I believe we will also find that the fields of ecology and evolution will also be equally as indebted to bacteria and archaea over time.
I felt it ought to be included in the freshman sequence we teach here at the University of Puget Sound. One semester is called “The Unity of Life,” and is an introduction to cell and molecular biology; the other semester is called “The Diversity of Life,” and focuses on ecology, groups of living things, and evolutionary topics. Here is what some of my students wrote in response to my question:
- I had never heard of biofilms before this class, yet they are common in nature (even involved in many human diseases)—this could fit into either semester in the first year.
- First year students should learn that Rubisco is a prokaryotic enzyme, not just found in plants (and that chloroplasts are enslaved cyanobacteria!). Also, that nitrogenase is prokaryotic, and what would happen if it stopped working.
- Why not present bacterial and archaean compartments when discussing eukaryotic compartmentalization (Golgi, ER, etc)? Bacteria aren’t “bags of enzymes.”
- Freshmen REALLY need to hear more about the archaea—both in class and in lab. They are not just extremophiles, either!
- Diversity of Life could include more microbial symbioses: leafcutter ants and Pseudonorcardia, or weird Wolbachia, or Buchnera. Maybe even a lab using PCR to search for Wolbachia in insects?
- I thought learning about antibiotics was really important to everyday life, and I’ll bet freshmen would feel the same way.
- Presenting a simple quorum sensing model could help freshmen see how cell-cell signaling works as a concept. It could prepare them for learning about more complicated eukaryotic cell-cell signaling in upper division courses, and getting them thinking about microbial communication early on. Could our QS lab exercise be adapted to the freshman class?
- Students should be hearing more about the prokaryotic role in elemental cycling . I really didn’t know how important prokaryotes were to those cycles.
- Could professors in our classes please quit calling bacteria “simple”? Also, could they stop telling us that bacteria don’t have cytoskeletons (because they do), and lack compartmentalization (because they have compartments)?
- Freshmen could hear more about the Tree of Life and how it came to be.
- I think that first year students could discuss the controversy over the term “prokaryote,” and learn a lot about microbiology by doing so.
To the above, I would simply add what Walt Whitman wrote many years ago: “We convince by our presence.” My students become “true believers” in microbial supremacy because I show them the centrality of the microbial world to almost every aspect of biology. We microbiologists do need to continue to preach our microbial gospel to freshmen!
Inspired by this, I am going to introduce some additional microbially oriented topics in my “The Unity of Life” course next semester: biofilms, antibiotics, quorum sensing, microbial interactions, and a new investigative laboratory exercise involving biofilms. Wish me luck at “occupying the curriculum.” Change can be challenging, in pedagogy as everywhere else. Still, I must try, because in the biosphere, our microbial relatives are far, far more than merely the “99%”!
Mark O. Martin is an avowed “microbial supremacist” as well as an Associate Professor of Biology at the University of Puget Sound in Tacoma, Washington. He is a frequent contributor to STC and was an Associate Blogger for several years.
Editor's Note: Mark puts his money where his mouth is and teaches what must be a dream undergraduate micro course (as judged by the students' ratings). As an example, see the "nanobiographies" that his students wrote as a class assignment.